Corrupted Raw Captures


Today’s Question: Until recently I had no problems at all when opening raw files in Camera Raw and the videos in Final Cut Pro X. Unfortunately, since a few days ago, here is what I get [random colored pixels in a mostly linear pattern] when opening the raw files in Camera Raw.

Tim’s Quick Answer: The sample images provided along with today’s question demonstrate clear signs of a corrupted raw capture. The key is to determine the component that is causing that corruption.

More Detail: When a raw capture file is corrupted the pixel data can’t be rendered properly. This will generally cause the image to have random patterns of colored pixels in a somewhat linear pattern. The colors will often be highly saturated, and the patterns may cover a portion of the image or the entire image.

Here is a sample of what this corruption can look like:

If a raw capture is corrupted in this way, there isn’t a way to recover the original photo. Instead, you’ll need to try to determine the source of the corruption.

The corruption can be caused anywhere from the camera to the computer, and all applicable devices in between. In other words, the corruption might be caused by the camera, by a faulty memory card, by a damaged card reader or cable used to connect the card reader to the computer, a faulty port on your computer, a faulty hard drive on your computer, or the computer itself.

In most cases I have found that a damaged memory card is the culprit, so I would start by capturing test photos on all cards you suspect may be the source of the problem. After capturing a relatively large number of photos on each card, if you find that photos are corrupted on only one of the cards than there is a very good chance that the card with the corrupted photos is to blame. In this case I would discard the problematic memory card, or see if it is eligible for a refund if it was purchased relatively recently.

If all the memory cards you test end up with corrupted photos, then the camera could be the source of corruption. However, it could also be the card reader or another component on your computer. The corrupted images won’t show any signs of corruption on the camera, because an embedded JPEG is used to show you the preview on the camera.

I would start by testing the captures on a completely different computer with entirely different components. Then gradually introduce the other components, such as your card reader and cable, to determine where the source of corruption is.

As noted above, in most cases the memory card is the source of corruption. Other likely candidates are the card reader and the camera. But it is also possible that any other component involved in writing the file to a new location could be causing the files to become corrupted.